package com.itheima.reggie.web;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

/**
 * 文件上传
 */
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {
    @Value("${reggie.path}")
    private String basepath;

    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) throws IOException {
        log.info(file.toString());
        //原始文件名
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));

        //使用UUID生成文件名，防止文件名重复对文件进行覆盖
        String fileName = UUID.randomUUID().toString()+suffix;

        //创建一个目录对象
        File dir = new File(basepath);
        //判断目录是否存在
        if (!dir.exists()){
            //不存在目录需要创建一个新目录
            dir.mkdirs();
        }
        //将临时文件转存到指定位置
        file.transferTo(new File(basepath + fileName));
        return R.success(fileName);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) throws Exception {
        //输入流，通过输入流读取文件内容
        FileInputStream fileInputStream = new FileInputStream(new File(basepath+name));
        //输出流，通过输出流将文件写回浏览器，在浏览器展示图片
        ServletOutputStream outputStream = response.getOutputStream();

        response.setContentType("image4/jpg");
        int len=0;
        byte[] bytes = new byte[1024];
        //读到的有效数据
        while ((len=fileInputStream.read(bytes))!=-1) {
        outputStream.write(bytes,0,len);
        outputStream.flush();
        }
        //关闭资源
        outputStream.close();
        fileInputStream.close();
    }
}
